One flag distance?

[EdLena]

When shooting 100 yards I see people often use 3 wind flags. If you could only use 1 flag at what distance would you place it.
We know that any wind drift on a pellet at close range will compound into a greater change in POI than a wind farther down range.
However a more mid range flag placement my be more indicative of the entire wind profile.
Any mathematicians out there?

[FBecigneul]

I’m a mathematician and I say 1 + 2 = 3
That may be the best number of flags.
Also, watch the flags on the lanes next to you. They will tell you before it’s too late.

[KimZ]

I've read convincing arguments that the most important flag (of a few, spaced evenly from bench to target) is the one near the bench. The reasoning is that the first deflecting wind has the biggest effect on downrange POI.

That makes sense but my match experience is different. Mid-range and target-area flags seem more significant than the flag near the bench, and watching them gives better results. I think this is because there is a lot of wind interference near the bench that makes flags in this area less relevant. ie, eddies off of sun roofs, adjacent structures, etc.

In other words, once the pellet leaves the zone of sun roof influence it is taken by winds in the open range.

[EdLena]

In other words, once the pellet leaves the zone of sun roof influence it is taken by winds in the open range.

That makes sense and I've noticed the same peculiar flag activity with the nearest flag. So just far enough from the building to be free of it's interference would be good, say 30 yards?

[KimZ]

I shoot at 25 meters so 30 yard wouldn't be much help

Usually the best approach is to experiment. Try different positions and see what works best.

[FBecigneul]

If you are going to only one range, you may be the best judge of where to deploy your one flag. There are influences at different distance at different ranges and general wind direction is also a factor. Place your flag where you feel it is more honest.

[HuskerP7M8]

I’m a mathematician and I say 1 + 2 = 3
That may be the best number of flags.
Also, watch the flags on the lanes next to you. They will tell you before it’s too late.

I'm not a mathematician, but you're dead wrong! The correct number of flags is 100 and you want them spaced every single yard. Of course, you also need an eidetic memory to remember the exact position of every single flag for every single shot and the judicious use of sighters. LOL

Landy

[HuskerP7M8]

When shooting 100 yards I see people often use 3 wind flags. If you could only use 1 flag at what distance would you place it.
We know that any wind drift on a pellet at close range will compound into a greater change in POI than a wind farther down range.
However a more mid range flag placement my be more indicative of the entire wind profile.
Any mathematicians out there?

Using the "Iterations" method in conjunction with a Point Mass Ballistics Solver, it appears 75% to 80% of what your flags are telling you in regards to where to hold on the target occurs in the first 2/3's of the distance to the target. Approximately 50% of the wind's influence occurs in the first 1/3 of the distance to the target.

If for whatever reason you're somehow forced to use a single flag, it's obvious closer is better, and it's also obvious that you actually have two flags and not one.
The feel of the wind on your hair and/or face on the firing line may be the very best flag in your arsenal and when forced to use one other single flag it might be best to position it somewhere farther downrange between maybe 1/3 and 2/3 of the distance to the target.

Also, and as Kim alluded to, any advice I have is going to be very range and condition specific. For example, the turbulence at the firing line is mostly eliminated with headwinds, but tailwinds could be very tricky to read at or near the bench. Conditions farther downrange can also be susceptible to error due to berms, trees, rise and fall of the terrain, etc.

I've shot enough different ranges over the years that it's become obvious to me you need to be flexible and change your plans based on range terrain and wind conditions.

I or someone else could run a "Monte Carlo" simulation in Excel using the variables of flag distance/target distance and might be able to come up with some hard numbers, but it would mostly be an academic exercise because a single flag just isn't going to provide you with enough data for any type of useful analysis.

Another proviso, I'm not certain if fin stabilization with pellets vs gyroscopic stabilization in RF/CF will behave the same. I do believe fin stabilization with pellets eliminates the Aerodynamic Jump we see in RF/CF and may result in the vertical deflection due to a crosswind being the polar opposite.

Yur gunna need more flags, or yur gunna need someone other than an amateur like me to provide better advice! LOL

Landy

[Wilbur]

If you're gonna set just one flag don't bother. Watch what flags are out there and look in the direction the wind is coming from. Truth is, that may be the best method of all. Problem is...you may get a bench away from the available flags and it would be good to have a few on hand.

[mrspradlin]

Many folks in the short range benchrest have talked about the “one flag” placement or “the most important flag” to watch.

Some say the closest flag because the wind pushing it right out of the barrel sends it off course right away and moving it further off your point of aim.
Some say the middle flag because you can feel, hear and see (grass moving and such) the wind near you.
A few say the flag furthest from the bench because thats the area the projectile is most vulnerable.

Can each one of these be correct? Absolutely.
Can each one of these be wrong? Absolutely as well.

The things that can help the most is learning how to read your wind flag or flags. And how your rifle handles the different conditions.